what should we consider before use ultrasonic welding 

Not all material and application suit for ultrasonic welding .The product needs to meet three basic conditions to achieve the desired effect by ultrasonic welding .

1. Whether the two plastic materials can be welded: Some materials can be welded better, some are basically melted, and some are not melted. The melting point between the same material is the same, and the principle is that it can be welded, but when the melting point of the workpiece to be welded is greater than 350 ° C, it is not suitable for ultrasonic welding. Since the ultrasonic is instantaneously melting the workpiece molecules, the judgment is based on 3 seconds, and the welding cannot be performed well, and other welding processes should be selected. Such as hot plate welding. Generally speaking, ABS material is the easiest to weld, and nylon or PP material is the most difficult to weld.

2. Plastic parts should be added with reasonable ultrasonic welding line. When the instantaneous energy is generated, the larger the joint area, the more serious the energy dispersion, the worse the welding effect, and even the welding. In addition, the ultrasonic wave is transmitted longitudinally, the energy loss is proportional to the distance, and the long distance welding should be controlled within 6 cm. The welding line should be controlled between 30----80 filaments. The wall thickness of the workpiece should not be less than 2 mm, otherwise it will not be welded well, especially for products requiring airtightness.

3. The product positioning structure should be designed reasonably: Before the product development and design, we should consider the appearance of the finished product. Whether the joint position of the two synthetic plastic parts is misplaced, it is wrong to rely on the ultrasonic fixing fixture to solve the misalignment after welding. If the product is placed too tightly, it will be scratched. The fixture will be enlarged by 0.1mm by default. If the product is not positioned, the finished product will have a 0.2mm misalignment. Ultrasonic manufacturers also have pneumatic or manual fixtures. Fixed products avoid misalignment, and production speed and fixture manufacturing costs can cause unnecessary expenses. Experienced engineers should know that products without an art line can easily cause misalignment of the upper and lower covers after assembly deformation, resulting in scratching. Ultrasound is also the same, there is also the probability of misplacement, in order to prevent the scratching of the hand, it is best to do a little art line on it.